Central to the Ayurvedic understanding of digestion is the strength of this digestive fire, called agni. Composed of various acids and enzymes, agni is seated within the lower stomach and small intestine and relates to Pitta dosha.

Ayurveda refers to an individual’s overall digestive capabilities in relation to agni (“Her agni is balanced,” for example). While it’s common to use the terms agni and “digestive fire” interchangeably, there are in fact a total of 13 different agnis governing all metabolic functions of the body. Any process involving heat, light, transformation, and conversion relates to agni. On a universal scale, agni is the creative flame of intelligence that is present in all life.

After an individual’s current doshic state, agni is the most important factor in determining dietary needs. It‘s a readily observable fact that we all digest food differently. One individual may gleam with satisfaction after a meal, while another person may clutch his stomach in agony after eating the exact same thing. For this reason, terms like “iron stomach” and “eating like a bird” have become everyday terms.

Common ways agni becomes weak or aggravated include: eating out of accordance with one’s constitution, habitually eating the same foods, overeating, eating tasteless foods, drinking too much water with meals, staying up late, eating at irregular times, and resisting the urge to eat, and not exercising enough.